Dhammapada questions on craving

When I picked up a version of the Dhammapada (Parallax Press) and read through I came across an interesting verse in this specific book it was Chapter 24: Craving . Forgive me for not knowing the verses, I'm new to the text. The verse says: > A man will be swept along > By the thirty-six streams of sensual pleasure, > Borne on the strong currents > Of his craving toward tempting objects. What are the 'thirty-six' streams of sensual pleasure? Is it some arbitrary enumeration, or is there some further writings detailing the 'thirty-six' streams of sensual pleasure?